This invention relates to an electronic musical instrument, in which external acoustic signals are recorded in a digital form and sounded at desired pitches, and more particularly, to an overdubbing apparatus for such an electronic musical instrument, which is capable of superimposing and recording a plurality of previously stored acoustic signals as another tone signal.
Heretofore, it has been in practice to store externally applied acoustic signals of musical sounds of musical instruments such as piano, violin, etc. or voices of birds in a memory in a digital form through a proper modulation system, e.g., PCM (pulse coded modulation) and read out the stored signals from the memory as tone signals of a keyboard musical instrument.
Copending U.S. patent applications Ser. Nos. 760,290 and 760,291 both filed July 29, 1985 and assigned to the same assignee as this application disclose a musical instrument of such a type as described above. The '290 application issued as U.S. Pat. No. 4,681,008 on July 21, 1987, and the '291 application issued as U.S. Pat. No. 4,667,556 on May 26, 1987.
This type of keyboard musical instrument or apparatus, which is called sampling machine, because of a sampling function, may be designed to have an overdubbing function, i.e., a function of superimposing a plurality of previously recorded acoustic signals to produce a separate tone signal. None of such apparatuses with overdubbing function, however, has yet been put into practice.